Some insomniacs may just be afraid of the dark

Scientists now say that many sleep problems can be traced to an anxiety that sparks as soon as the lights go down, according to a new study presented at the annual meeting of the Associated Professional Sleep Societies.

The small study found that 50 percent of adults who reported sleep problems also admitted to being scared of the dark - and were also measurably more anxious when the lights were turned off.

“The good news, is that if this is what is going on, it’s very treatable,” said the study’s lead author Colleen Carney, an associate professor at Ryerson University in Toronto. “And it doesn’t take long to treat.”

To see if bad sleep might be phobia driven, Carney and her colleagues rounded up 93 college students and asked them to fill out surveys that included questions about their sleep quality and whether they were afraid of the dark.

Then the researchers ran an intriguing experiment: In the first half of the experiment the volunteers sat in a room with the lights on. In the second half, they sat with the lights off. All the while, the volunteers were wearing headsets that would periodically play a blast of noise.

“Then we watched their reactions in the light and the dark,” Carney said. “In the light they were no different. But in the dark, the poor sleepers were more likely to be startled.”

In other words, compared to the sound sleepers, the insomniacs were more likely to blink and to flinch when they heard the noise in the dark. In fact, the more times they heard the noise, the more anxious and jumpy they got. The good sleepers, in contrast, got used to hearing the noise and eventually stopped reacting to it.

Fear of the dark isn’t something that sleep doctors currently look for, Carney said. So the new research might open new avenues for treatment.

And the good news is that phobias often respond very quickly to treatment with exposure therapy, Carney added. So, just as a therapist can get you used to spiders and snakes by slowly exposing you to them, they’ll also be able get you over your fear of the dark.